International Journal

We present an overview on epitaxial growth, processing technology, device performance, and reliability of our GaN high electron mobility transistors (HEMTs) manufactured on 3- and 4-in. SiC substrates. Epitaxy and processing are optimized for both performance and reliability. We use three different gate lengths, namely 500 nm for 1?6 GHz applications, 250 nm for devices between 6 and 18 GHz, and 1

The present paper presents an overview of the AlGaN/GaN-based circuits realized over the years. Two technological processes with 0.25 and 0.7 ?m gate length allowed one to address applications from L- to Ku-bands. Depending on the process development and frequency of the operation, results on hybrid or MMIC technology are presented. GaN technology is evaluated through the realization of high-power

GaN technology has gained a lot of attention in Europe over the last few years for various domains including RF electronics. After a few years of active observation, United Monolithic Semiconductors (UMS) has taken the decision to introduce a GaN technology family in its portfolio. Based on its extensive experience of III?V technology and the intensive support and collaboration with partners and E

The present paper presents the transistor modeling work achieved in the GaN European project KorriGaN (?Key Organisation for Research in Integrated Circuits in GaN technology?). The KorriGaN project (2005?09) has released 29 GaN circuits such as high-power amplifiers (HPAs), low-noise amplifiers (LNAs), and switches. Modeling is one of the main key to reach successful designs. Therefore, nonlinear

In the present paper we review the most recent degradation modes and mechanisms recently observed in AlGaN/GaN (Aluminum Gallium Nitride/Gallium Nitride). High Electron-Mobility Transistors (HEMTs), as resulting from a detailed accelerated testing campaign, based on reverse bias tests and DC accelerated life tests at various temperatures. Despite the large efforts spent in the last few years, and

This work presents a measurement-based physics-oriented large-signal modeling technique for GaN HEMTs. All the model elements are derived directly from pulsed-DC measurements and bias dependent small-signal model elements. The proposed small-signal model features a 12-element extrinsic network, which allows proper modeling of the complex parasitic effects present in large gate-width devices. A rel

The aim of the present paper is to highlight the possible benefits coming from the use of the GaN high electron-mobility transistor (HEMT) technology in the Doherty power amplifier (DPA) architecture. In particular, the attention is focused on the capabilities and the relevant drawbacks of a GaN HEMT technology when designing DPAs. A deep discussion of the DPA's design guidelines is also presented

The present paper presents the design and development of a dual-channel microwave rotary joint using coaxial waveguide as primary waveguide and rectangular waveguide as the secondary waveguide. Design is presented at 5.85?7.02 GHz with 20% bandwidth and at 14?14.5 GHz bands with 3.6% bandwidth using dual channel mode transducers exciting transverse electromagnetic (TEM) mode in the coaxial wavegui

The present paper presents a very efficient technique for enhancing the pointing accuracy in beam-waveguide (BWG) antennas and its application to the deep space antenna DSA2 of the European Space Agency. The proposed technique permits to achieve a twofold result: on the one hand, it provides a solution to the beam aberration issue, arising when the antenna simultaneously receives from and transmit

This paper presents a detailed experimental analysis of the cyclostationary properties of low-frequency (LF) noise sources of microwave bipolar devices, in order to improve the LF noise description in compact models. Such models are used to help designers on predicting circuit performances such as phase and amplitude noise in oscillators. We start by reviewing the most relevant experimental and si